ptcon Interface

public interface ptcon

PTCON computes the reciprocal of the condition number (in the 1-norm) of a complex Hermitian positive definite tridiagonal matrix using the factorization A = LDLH or A = UHDU computed by CPTTRF. Norm(inv(A)) is computed by a direct method, and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).


Subroutines

public pure subroutine cptcon(n, d, e, anorm, rcond, rwork, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(in) :: d(*)
complex(kind=sp), intent(in) :: e(*)
real(kind=sp), intent(in) :: anorm
real(kind=sp), intent(out) :: rcond
real(kind=sp), intent(out) :: rwork(*)
integer(kind=ilp), intent(out) :: info

public pure subroutine dptcon(n, d, e, anorm, rcond, work, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(in) :: d(*)
real(kind=dp), intent(in) :: e(*)
real(kind=dp), intent(in) :: anorm
real(kind=dp), intent(out) :: rcond
real(kind=dp), intent(out) :: work(*)
integer(kind=ilp), intent(out) :: info

public pure subroutine sptcon(n, d, e, anorm, rcond, work, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(in) :: d(*)
real(kind=sp), intent(in) :: e(*)
real(kind=sp), intent(in) :: anorm
real(kind=sp), intent(out) :: rcond
real(kind=sp), intent(out) :: work(*)
integer(kind=ilp), intent(out) :: info

public pure subroutine zptcon(n, d, e, anorm, rcond, rwork, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(in) :: d(*)
complex(kind=dp), intent(in) :: e(*)
real(kind=dp), intent(in) :: anorm
real(kind=dp), intent(out) :: rcond
real(kind=dp), intent(out) :: rwork(*)
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_cptcon()

Arguments

None

public interface stdlib_dptcon()

Arguments

None

public interface stdlib_sptcon()

Arguments

None

public interface stdlib_zptcon()

Arguments

None